>if you want to sign up users through Apple's infrastructure, which has a cost associated with it, you have to pay the same price as everyone else.

And if you don't, you're out of luck due to the increasingly hostile restrictions on what you're allowed to even mention in the app - at least according to the website.

Can't say I'm 100% on Spotify's side, but to me it doesn't seem like Apple has anything stand on here, ethics-wise. Microsoft and the IE case comes to mind.